Devices to adjust the orientation of a mirror are used in a door mirror vehicle. These devices comprise electric motors whose shafts are connected via transmission means with the mirror.
These devices comprise a housing accommodating a first and a second electric motor and a first and a second gear driven by said first and second motor respectively, a mirror support pivot-mounted at the housing in relation to two pivot axles, at which two gear knees are arranged engaging with said gears, a first gear knee engaging with the first gear to pivot the mirror support around a first pivot axle and a second gear knee engaging with the second gear to pivot the mirror support around a second pivot axle.
Each gear knee is fixed arranged directly at the mirror support so the necessary forces to set the orientation of the mirror support are only applied. in two points of the mirror support forming 90° with the center of the mirror support, wherein there isn't any other point in a circumferential arc of 270° in the mirror support receiving the forces from first and second gears.
This configuration distributes forces in a non simetrical way to the mirror support thus increasing the efforts in a specific area of the mirror support and in consecuence causing vibrations in the above mirror support.
Another consecuence of the above configuration is that a manual movement of the door mirror causes worn smooth of the gear knee's teeth since efforts are only absorbed by two points of the mirror support.
In another known configuration forces from gears are applied on four points of the mirror support, three of them equidistantly located in a 90° arc and the other one opposite to the centred point of the three equidistant points.
This configuration also distributes forces in a non-simetrical way to the mirror support since the fixing point of each gear knee is nos connected to the other two points thus increasing the efforts in the specific area of the three equidistant points and in consecuence making convex the mirror support after a high number of working cycles.
Document EP1630040 discloses a mirror support which is arranged in a ball-and-socket joint way to the gears wherein the movement is driven by two gear knees acting in the plane perpendicular to that defined by the mirror in its rest position so there are only three support point non equidistant.
All the above disadvantages are overcome by the present invention that is going to be described in the following sections.